I got a query today about a limit of the number of component on a CRM Dashboard, the customer was getting the error "Maximum number of components allowed is 6" has he was trying to create a new dashboard.
Hopefully, it was an On Premise installation and it's a deployment setting you can change (at least on premise).
Start Windows Power Shell on the deployment server console (the icon looks like this) and type the following commands :
$setting = Get-CrmSetting -SettingType DashboardSettings
$setting.MaximumControlsLimit = enter the maximum dashboard components number (ie: 9)
Set-CrmSetting -Setting $setting